Mydriacyl (Tropicamide)
Mydriatic Eye Drops for Diagnostic Pupil Dilation
Quick Facts About Mydriacyl
Key Takeaways About Mydriacyl
- Short-acting mydriatic: Tropicamide dilates the pupil within 15–30 minutes, with effects lasting 4–8 hours – the shortest duration among commonly used mydriatics
- Diagnostic use only: Mydriacyl is used to dilate pupils for eye examinations and is not a therapeutic treatment for eye conditions
- Do not drive after use: Blurred vision and light sensitivity can persist for several hours after administration; arrange alternative transport
- Glaucoma risk: Do not use if you have narrow-angle glaucoma or a shallow anterior chamber, as it can trigger an acute rise in intraocular pressure
- Extra caution in infants: Only the 0.5% concentration should be used in infants; premature babies, children with Down syndrome, or neurological conditions are at higher risk of systemic side effects
What Is Mydriacyl and What Is It Used For?
Mydriacyl (tropicamide) is a mydriatic eye drop that dilates the pupil and temporarily paralyses the focusing muscles of the eye. It is primarily used before diagnostic eye examinations to allow healthcare professionals to examine the internal structures of the eye, including the retina and optic nerve.
Mydriacyl 0.5% eye drops contain the active substance tropicamide, which belongs to a group of medications called anticholinergic (parasympatholytic) mydriatics. These drugs work by blocking the action of acetylcholine on the muscarinic receptors of two key muscles in the eye: the sphincter muscle of the iris (which controls pupil size) and the ciliary muscle (which controls the eye's ability to focus on nearby objects). By blocking these receptors, tropicamide causes the pupil to dilate widely (mydriasis) and temporarily prevents the eye from adjusting its focus (cycloplegia).
The primary clinical application of Mydriacyl is in diagnostic ophthalmology. When the pupil is dilated, it allows the ophthalmologist or optometrist to perform a comprehensive examination of the posterior segment of the eye. This includes detailed assessment of the retina, the macula (the central part of the retina responsible for sharp central vision), the optic disc (where the optic nerve enters the eye), and the retinal blood vessels. These examinations are essential for detecting and monitoring conditions such as diabetic retinopathy, age-related macular degeneration, retinal detachment, glaucoma, and various other ocular diseases.
Tropicamide is favoured over older mydriatic agents such as atropine and cyclopentolate because of its rapid onset and short duration of action. While atropine can cause pupil dilation lasting 7 to 14 days, tropicamide's effects typically resolve within 4 to 8 hours. This means patients experience less disruption to their daily activities following a dilated eye examination. According to the American Academy of Ophthalmology (AAO), tropicamide is the mydriatic of choice for routine fundus examinations.
In clinical practice, tropicamide is sometimes used in combination with phenylephrine (an alpha-adrenergic agonist) to achieve greater and more rapid pupil dilation. This combination approach is particularly useful when maximum mydriasis is required, such as prior to retinal surgery or laser procedures. The combination produces both a parasympathetic block (from tropicamide) and a sympathetic stimulation (from phenylephrine), resulting in more effective dilation than either agent alone.
Tropicamide was first synthesised in 1959 and has been widely used in clinical ophthalmology for over six decades. It is included on many national essential medicines lists and remains the global standard for diagnostic pupil dilation due to its excellent safety profile and short duration of action. The medication is administered only in clinical settings by healthcare professionals or under their direct supervision.
What Should You Know Before Using Mydriacyl?
Before Mydriacyl is administered, your eye care professional should be informed about any existing eye conditions (particularly glaucoma), all medications you are currently taking, and whether you are pregnant or breastfeeding. Mydriacyl is contraindicated in patients with narrow-angle glaucoma or shallow anterior chamber angles.
Contraindications
Mydriacyl should not be used if any of the following apply:
- Allergy to tropicamide or any other ingredient in the eye drops (including the preservative benzalkonium chloride) – symptoms may include itching, redness, swelling, or difficulty breathing
- Narrow-angle glaucoma or a known shallow anterior chamber angle – pupil dilation can block the drainage of aqueous humour from the eye, causing a sudden and potentially dangerous rise in intraocular pressure (acute angle-closure glaucoma)
If you have been diagnosed with any form of glaucoma, or if you have been told that you have narrow drainage angles in your eyes, it is essential to inform your eye care professional before receiving Mydriacyl. Acute angle-closure glaucoma is a medical emergency that requires immediate treatment to prevent permanent vision loss.
Warnings and Precautions
Talk to your doctor or eye care professional before using Mydriacyl if any of the following apply:
- Elevated intraocular pressure: Even in patients without known glaucoma, tropicamide can cause a temporary increase in intraocular pressure. Your eye care professional should measure your intraocular pressure before administering the drops, especially if you have risk factors for glaucoma
- Elderly patients: Older adults may be more susceptible to the systemic anticholinergic effects of tropicamide, including confusion, drowsiness, dry mouth, and urinary retention
- Patients with cardiovascular disease: Systemic absorption of tropicamide can occasionally cause tachycardia (rapid heart rate) and changes in blood pressure
- Patients with prostatic hyperplasia: The anticholinergic effects may worsen urinary retention
- Patients with gastrointestinal obstruction: Anticholinergic effects can reduce bowel motility
To minimise systemic absorption and reduce the risk of side effects, your eye care professional may instruct you to press gently on the inner corner of the eye (punctal occlusion) for approximately 2 minutes after the drops are instilled. This technique blocks the nasolacrimal duct and prevents the medication from draining into the nose and throat, where it could be absorbed into the bloodstream.
Use in Children
Mydriacyl can be used in children, but particular caution is required in certain populations:
- Infants: Only the 0.5% concentration should be used, as higher concentrations carry a greater risk of serious systemic side effects
- Premature and low-birth-weight neonates: These infants are at significantly increased risk of systemic toxicity due to their immature metabolism and lower body weight
- Children with Down syndrome: These children show increased sensitivity to anticholinergic drugs and may develop systemic side effects at lower doses
- Children with spastic paralysis or brain damage: Increased risk of central nervous system adverse effects
- Children with epilepsy: Anticholinergic agents may lower the seizure threshold in susceptible individuals
If Mydriacyl accidentally contacts skin around the eye rather than entering the eye itself, it should be washed off immediately with water to prevent inadvertent systemic absorption through the skin, particularly in young children.
Signs of systemic toxicity in children can include flushed, dry skin (or a rash), rapid and irregular heartbeat, fever, abdominal distension (in infants), seizures, hallucinations, and loss of coordination. If any of these symptoms develop after receiving Mydriacyl, seek immediate medical attention.
Pregnancy and Breastfeeding
The safety of Mydriacyl during pregnancy has not been adequately studied. Animal reproduction studies are insufficient to determine whether tropicamide poses a risk to the developing foetus. Mydriacyl should not be used during pregnancy unless the potential benefit to the mother clearly outweighs any potential risk to the foetus. If a dilated eye examination is medically necessary during pregnancy, your ophthalmologist will assess the risks and benefits on a case-by-case basis.
It is not known whether tropicamide passes into human breast milk after topical ocular application. However, as many drugs are excreted in human milk, and because of the potential for adverse anticholinergic effects in the nursing infant, Mydriacyl should not be used during breastfeeding. If a dilated eye examination is essential, your doctor may advise you to express and discard breast milk for a period after administration.
Driving and Operating Machinery
Mydriacyl causes blurred vision, impaired near vision, and increased light sensitivity (photophobia). These effects can significantly impair your ability to drive or operate machinery safely. You should not drive or operate machinery until these effects have fully resolved, which typically takes 4 to 8 hours but may last longer in some individuals. It is strongly recommended that you arrange alternative transportation before attending an eye appointment where pupil dilation is planned. Wearing sunglasses after the examination can help reduce discomfort from light sensitivity.
Contact Lenses and Benzalkonium Chloride
Mydriacyl eye drops contain benzalkonium chloride (0.1 mg/ml) as a preservative. This substance can be absorbed by soft contact lenses and may cause discolouration of the lenses. You must remove your contact lenses before Mydriacyl is administered and wait at least 15 minutes after the drops are applied before reinserting them.
Benzalkonium chloride can also be irritating to the eyes, particularly in patients with dry eye disease or corneal problems (disorders of the clear front surface of the eye). If you experience persistent irritation, stinging, or pain in the eye after receiving Mydriacyl, inform your eye care professional promptly.
How Does Mydriacyl Interact with Other Drugs?
Mydriacyl can interact with other medications that have anticholinergic properties, potentially amplifying systemic side effects such as dry mouth, rapid heartbeat, confusion, and urinary retention. Always inform your eye care professional about all medications you are taking.
Although Mydriacyl is applied topically to the eye, a proportion of the dose can be absorbed into the systemic circulation via the nasolacrimal duct and the conjunctival blood vessels. This systemic absorption means that drug interactions are possible, particularly with other medications that have anticholinergic (antimuscarinic) properties. The risk of clinically significant interactions is generally low in adults but is more relevant in children, elderly patients, and individuals receiving multiple anticholinergic medications.
Significant Interactions
| Drug / Class | Type | Effect | Recommendation |
|---|---|---|---|
| Antihistamines (e.g. diphenhydramine, chlorpheniramine) | Additive anticholinergic | Enhanced anticholinergic side effects: dry mouth, urinary retention, confusion, tachycardia | Inform your doctor; monitor for increased side effects |
| Tricyclic antidepressants (e.g. amitriptyline, nortriptyline) | Additive anticholinergic | Amplified systemic anticholinergic effects including confusion, constipation, urinary retention | Use punctal occlusion to minimise absorption; monitor carefully |
| Phenothiazines (e.g. chlorpromazine, promethazine) | Additive anticholinergic | Increased risk of anticholinergic toxicity and central nervous system depression | Use with caution; apply punctal occlusion after instillation |
| Amantadine | Additive anticholinergic | Increased anticholinergic side effects | Monitor for systemic anticholinergic symptoms |
| Quinidine | Additive anticholinergic | Enhanced anticholinergic effects and potential cardiac conduction changes | Use with caution in patients with cardiac disease |
| Other ophthalmic drugs | Administration timing | Potential dilution or altered absorption if applied too close together | Wait at least 5 minutes between different eye drops; apply ointments last |
Patients who are taking multiple medications with anticholinergic properties (a phenomenon known as "anticholinergic burden") should be particularly cautious. The cumulative anticholinergic load from systemic medications combined with topical tropicamide can increase the risk of adverse effects, especially in elderly patients. A comprehensive medication review before administering Mydriacyl is good clinical practice.
There are no known clinically significant interactions between tropicamide and common medications such as paracetamol (acetaminophen), ibuprofen, statins, or most antihypertensive drugs. However, it is always advisable to inform your healthcare provider about all medications, including over-the-counter products, vitamins, and herbal supplements.
What Is the Correct Dosage of Mydriacyl?
The recommended dose for adults is 2 drops of Mydriacyl 0.5% in the affected eye(s) approximately 20 to 25 minutes before the eye examination. For children, the dose is determined individually by the treating physician. Only the 0.5% concentration should be used in infants.
Mydriacyl is administered by your eye care professional or under their supervision. The dosage depends on the patient's age, the purpose of the examination, and the degree of dilation required. It is important to follow the specific instructions given by your doctor or ophthalmologist.
Adults (Including Elderly)
Standard Diagnostic Dose
2 drops of Mydriacyl 0.5% instilled into the conjunctival sac of the eye(s) to be examined, 20 to 25 minutes before the planned examination. Mydriasis typically begins within 15–30 minutes and reaches maximum effect at 20–40 minutes after instillation.
In elderly patients, the same dosage applies, but particular attention should be paid to monitoring for systemic anticholinergic effects, as older adults may be more susceptible to these side effects. Punctal occlusion (pressing gently on the inner corner of the eye) for 2 minutes after instillation is especially important in this population to minimise systemic absorption.
Children
Paediatric Dose
The dose is determined individually by the treating physician based on the child's age, weight, and clinical indication. Only the 0.5% concentration should be used in infants. Special caution is required for premature neonates, infants with Down syndrome, spastic paralysis, or brain damage.
In paediatric ophthalmology, tropicamide may be used alone or in combination with cyclopentolate when more complete cycloplegia is needed (for example, when measuring refractive errors in young children). The combination regimen and dosing schedule should be determined by the treating paediatric ophthalmologist.
How to Use Mydriacyl Correctly
Mydriacyl is designed to be instilled directly into the eye. It must never be injected. The following steps ensure correct administration:
- If the safety collar on the bottle is loose after removing the cap, remove it before using the product
- Wash your hands thoroughly before handling the eye drops
- Tilt your head back and gently pull down the lower eyelid to create a small pocket between the eyelid and the eye
- Hold the bottle tip close to the eye without touching the eye, eyelid, or surrounding skin – contact with these surfaces can contaminate the solution
- Gently squeeze the bottle to release one drop at a time into the pocket formed by the lower eyelid
- After instilling the drops, close your eye gently and press a finger against the inner corner of the eye (near the nose) for approximately 2 minutes – this reduces systemic absorption
- If treating both eyes, repeat the procedure for the other eye
- Replace the cap immediately after use
If a drop misses the eye, wipe it away immediately (especially in children) and try again. If you are using other eye drops or ointments, wait at least 5 minutes between each medication. Eye ointments should be applied last.
Missed Dose
Since Mydriacyl is typically administered as a single dose before an eye examination, a missed dose is not usually applicable. If your appointment required dilation and the drops were not administered in time, your eye care professional will determine the appropriate course of action, which may include rescheduling the examination or waiting for the drops to take full effect.
Overdose
If too much Mydriacyl has been accidentally instilled into the eye, flush the eye thoroughly with lukewarm water. Do not apply any additional drops until instructed to do so by your doctor.
If Mydriacyl is accidentally swallowed (for example, if a child ingests the solution), seek immediate medical attention or contact your local poison control centre. Symptoms of systemic overdose may include:
- Skin: Flushed, dry skin; rash (particularly in children)
- Eyes: Blurred vision, widely dilated pupils
- Heart: Rapid and irregular heartbeat (tachycardia)
- General: Fever, abdominal distension (in infants), seizures, hallucinations, loss of coordination, dry mouth
If a child has accidentally swallowed Mydriacyl, contact your local emergency services or poison control centre immediately. Treatment is supportive and may include physostigmine as an antidote in severe cases of anticholinergic toxicity.
What Are the Side Effects of Mydriacyl?
The most common side effects of Mydriacyl are temporary stinging upon application, blurred near vision, and light sensitivity. Systemic side effects (affecting the whole body) can occur, particularly in children and elderly patients, and include skin flushing, rapid heartbeat, fever, and confusion.
Like all medications, Mydriacyl can cause side effects, although not everyone will experience them. Side effects are categorised below by how frequently they occur. The risk of systemic side effects can be reduced by applying punctal occlusion (pressing on the inner corner of the eye) for 2 minutes after instillation.
Common
Affects 1 to 10 in every 100 people
- Eye effects: Temporary stinging or burning sensation when drops are applied (eye pain), impaired near vision, light sensitivity (photophobia)
- Systemic effects: Skin flushing, rapid heartbeat (tachycardia), fever, constipation, confusion, agitation, hallucinations
Uncommon
Affects 1 to 10 in every 1,000 people
- Allergic reactions (hypersensitivity)
- Difficulty urinating (urinary retention)
Rare
Affects 1 to 10 in every 10,000 people
- Acute rise in intraocular pressure (acute angle-closure glaucoma) – a medical emergency requiring immediate treatment
Not Known
Frequency cannot be estimated from available data
- Eye effects: Blurred vision, prolonged pupil dilation, eye irritation, eye redness, reduced tear production
- General effects: Dizziness, headache, fainting (syncope), low blood pressure, nausea, skin rash, dry mouth, reduced bowel motility, inability to urinate, dry mucous membranes, reduced sweating, dryness of the airways and nasal passages
Additional Side Effects in Children
Premature neonates, low-birth-weight infants, young children, and children with central nervous system disorders (such as epilepsy, brain damage, or Down syndrome) are at increased risk of systemic toxic effects from tropicamide. These effects can manifest as:
- Central nervous system disturbances: Confusion, agitation, hallucinations, seizures, loss of coordination, drowsiness
- Cardiovascular effects: Rapid and irregular heartbeat, changes in blood pressure
- Respiratory effects: Dryness of the airways, altered breathing pattern
- Gastrointestinal effects: Abdominal distension, reduced bowel sounds, feeding difficulties
Parents and caregivers should be aware of these potential effects and seek medical attention promptly if any concerning symptoms develop after their child receives tropicamide eye drops. The risk of systemic effects can be significantly reduced by careful dosing, use of the 0.5% concentration only, and consistent application of punctal occlusion technique.
If you experience any side effects from Mydriacyl, including those not listed above, report them to your healthcare provider. You can also report suspected adverse reactions to your national pharmacovigilance authority (e.g. the FDA MedWatch programme in the United States, the Yellow Card Scheme in the United Kingdom, or the EMA EudraVigilance system in Europe). Reporting helps monitor the ongoing safety of medicines.
How Should You Store Mydriacyl?
Store Mydriacyl out of the sight and reach of children. The opened bottle should be discarded 4 weeks after first opening. No special storage conditions are required.
Correct storage of Mydriacyl is important to maintain the sterility and efficacy of the eye drops. Follow these guidelines:
- Keep out of sight and reach of children: Accidental ingestion of tropicamide eye drops by a child can cause serious systemic toxicity
- Check the expiry date: Do not use Mydriacyl after the expiry date printed on the packaging (marked "EXP"). The expiry date refers to the last day of the stated month
- Discard 4 weeks after opening: Once the multi-dose bottle has been opened, it should be used within 4 weeks and then discarded, even if there is solution remaining. This is to maintain the sterility of the product
- No special storage conditions: Mydriacyl does not require refrigeration and can be stored at normal room temperature
- Disposal: Do not dispose of eye drops via the sink, toilet, or household waste. Return unused medication to your pharmacy for safe disposal to protect the environment
Single-dose units (preservative-free formulations), if available, should be used immediately after opening and any unused solution discarded. Single-dose units do not contain preservatives and therefore cannot be stored after opening.
What Does Mydriacyl Contain?
Each millilitre of Mydriacyl 0.5% eye drops contains 5 mg of tropicamide as the active ingredient, along with benzalkonium chloride (preservative) and other excipients to maintain the solution's stability and pH.
Active Ingredient
The active substance is tropicamide. Each millilitre of solution contains 5 mg of tropicamide (equivalent to a 0.5% w/v concentration).
Other Ingredients (Excipients)
The other ingredients in Mydriacyl are:
- Benzalkonium chloride – preservative (0.1 mg/ml, equivalent to 0.0035 mg per drop)
- Sodium chloride – tonicity agent (maintains isotonicity with tears)
- Disodium edetate (EDTA) – chelating agent (stabiliser)
- Hydrochloric acid and/or sodium hydroxide – pH adjustment
- Purified water – solvent
Appearance and Packaging
Mydriacyl is a clear, colourless to pale yellow solution supplied in a 15 ml low-density polyethylene (DROPTAINER) bottle with a polypropylene screw cap. The DROPTAINER system is designed to deliver controlled, single drops with gentle pressure on the bottle base. The product is manufactured by Alcon, a global leader in eye care.
Frequently Asked Questions About Mydriacyl
Mydriacyl (tropicamide) is used to dilate the pupil for diagnostic eye examinations. When the pupil is widened, it allows the ophthalmologist or optometrist to examine the internal structures of the eye, including the retina, optic nerve, and macula. This is essential for detecting conditions such as diabetic retinopathy, macular degeneration, retinal detachment, and glaucoma. Mydriacyl is the most commonly used mydriatic agent for routine dilated fundus examinations due to its rapid onset and short duration of action.
Mydriacyl begins dilating the pupil within 15 to 30 minutes after instillation. Maximum dilation is typically achieved at 20 to 40 minutes. The mydriatic effect (dilated pupil) usually lasts 4 to 8 hours, although some patients may experience blurred vision and light sensitivity for up to 24 hours, particularly with brown or dark irides. Tropicamide has the shortest duration of action among commonly used mydriatic agents, which is why it is preferred for routine examinations.
No, you should not drive after receiving Mydriacyl eye drops. The medication causes blurred near vision, difficulty focusing, and increased sensitivity to light, which can significantly impair your ability to drive safely. These effects typically last 4 to 8 hours. It is strongly recommended that you arrange for someone to drive you home from your appointment or plan to use public transport or a taxi. Wearing dark sunglasses after the examination can help with the light sensitivity.
Mydriacyl can be used in children, but only the 0.5% concentration should be used in infants to minimise the risk of systemic side effects. Premature babies, infants, and children with Down syndrome, cerebral palsy, or brain injuries are at increased risk of systemic toxicity. The paediatric ophthalmologist will determine the appropriate dose based on the child's age and weight. Parents should watch for signs of systemic effects such as flushed skin, rapid heartbeat, fever, or unusual behaviour after the drops are administered.
A temporary stinging or burning sensation when Mydriacyl is instilled is a common and expected side effect. This discomfort is usually mild and subsides within a few seconds to minutes. Close your eyes gently and apply gentle pressure to the inner corner of the eye for about 2 minutes after application. If the stinging is severe, persistent, or accompanied by significant eye redness, swelling, or pain, inform your eye care professional immediately, as this may indicate an allergic reaction or sensitivity to the solution or its preservative (benzalkonium chloride).
Mydriacyl can trigger an acute attack of angle-closure glaucoma in patients who have narrow drainage angles in their eyes. This is a rare but serious complication that constitutes a medical emergency. Symptoms include sudden severe eye pain, headache, nausea, vomiting, blurred vision, and seeing haloes around lights. If you experience any of these symptoms after receiving Mydriacyl, seek immediate medical attention. Your eye care professional should assess your anterior chamber angles before administering mydriatic drops to identify patients at risk.
References
This article is based on the following evidence-based sources and international guidelines:
- European Medicines Agency (EMA). Tropicamide Summary of Product Characteristics. EMA approved SmPC. Available at: ema.europa.eu
- American Academy of Ophthalmology (AAO). Preferred Practice Patterns: Comprehensive Adult Medical Eye Evaluation. AAO, 2020. Available at: aao.org
- British National Formulary (BNF). Tropicamide – Drug Monograph. NICE Evidence Services. Available at: bnf.nice.org.uk
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd List, 2023. Geneva: WHO, 2023.
- Manny RE, Fern KD, Zervas HJ, et al. 1% Tropicamide as a diagnostic mydriatic: a reappraisal. Optometry and Vision Science. 1993;70(12):1007–1011.
- Loewen N, Liu JHK. Mydriatics and cycloplegics. In: Albert DM, Miller JW, eds. Albert & Jakobiec's Principles and Practice of Ophthalmology. 3rd ed. Philadelphia: Elsevier; 2008.
- Farkouh A, Frigo P, Girst M. Ocular pharmacology of tropicamide: a systematic review. Expert Opinion on Drug Metabolism & Toxicology. 2016;12(9):1035–1045.
- National Institute for Health and Care Excellence (NICE). Glaucoma: diagnosis and management. NICE guideline NG81. Updated 2022.
Editorial Team
This article has been written and medically reviewed by the iMedic Medical Editorial Team, comprising licensed physicians specialising in ophthalmology, clinical pharmacology, and evidence-based medicine.
iMedic Medical Writers – experienced medical content creators with expertise in translating complex pharmacological data into accessible patient information. All content follows the GRADE evidence framework and international editorial standards.
iMedic Medical Review Board – independent panel of board-certified physicians who verify all medical claims against current international guidelines (EMA, AAO, NICE, WHO). Every article undergoes rigorous fact-checking before publication.
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